1. Field of the Invention
The present invention relates generally to movable insulation and window coverings and, more particularly, to devices and processes for manufacturing the same. More specifically, the present invention relates to an improved process and apparatus for producing expandable honeycomb material useful as window coverings and movable insulation.
2. Description of The Prior Art
Energy conservation techniques and devices have grown substantially in popularity over the last fifteen years or so. These techniques have included innovative passive solar designs as well as retrofitting existing structures to increase energy conservation and reduce energy utilization. New passive solar designs frequently incorporate a great deal of glass surface. However, in such designs as well as in more conventional window designs, substantial energy loss during the evening hours and winter months can occur through such window structures. Consequently, numerous shading devices having insulative properties have been designed for use with window structures to permit maximum solar gain during daylight hours while insulating the window structures to reduce energy loss during evening hours, cloudy days and the like.
As a result of the above, thermal insulating blinds or shades having a honeycomb-type structure have been devised for use with windows and the like. Examples of such honeycomb structures are disclosed in U.S. Pat. Nos. 4,019,554 and 4,346,132. British Patent Specification No. 1,308,296 also discloses such honeycomb material useful as an energy shade or blind for windows. Interestingly, the popularity of such honeycomb blinds has grown beyond mere energy conservation applications. Such honeycomb structures have become very popular as substitutes for more established window coverings and shades such as venetian blinds, thin louvered blinds and the like. An example of such honeycomb fashion blinds are those manufactured and sold under the trademark "DUETTE" by Hunter Douglas Corporation. Thus, such honeycomb structures have applications in a wide variety of market segments.
As such honeycomb structures have grown in popularity, a need has developed for more efficient and cost effective methods of manufacturing honeycomb insulation and shading structures. A principal method and device for achieving this is disclosed in U.S. Pat. No. 4,450,027. This particular process and device is designed expressly to manufacture expandable honeycomb material of the type useful in the above applications. While the disclosed apparatus and process have generally functioned quite well, there are some disadvantages to this particular technique. One of the principal drawbacks is that there is an excess amount of material waste as a result of the type of rack upon which the honeycomb material is accumulated. Moreover, there is also additional waste and flawed material as a result of the stacking of the folded material in multiple layers under tension at the same time that the adhesive is still in a liquid state and in the process of drying. This causes, at times, adhesive to bleed through and thereby interconnect multiple layers of honeycomb material, thus thereby requiring that this portion of the material be cut out and discarded. Finally, the prior method for folding, applying adhesive and winding the tubular material requires extensive and complicated tension control arrangements to achieve the desired end result of a plurality of interconnected tubular members forming expandable honeycomb.
Other devices and methods for producing honeycomb are even more complicated and unsatisfactory than that disclosed in the above referenced patent. In addition, such other prior art devices tend to produce warps and wrinkles in the material which are unsatisfactory and unacceptable. Finally, some prior attempts have also included exceedingly cumbersome machinery having many strips of material running simultaneously to form the honeycomb.